1. Field
One or more aspects of embodiments according to the present invention relate to organic light emitting display apparatuses and methods of manufacturing the same.
2. Description of the Related Art
In general, an organic light emitting device (OLED) has a structure in which an organic light emission layer formed as a functional thin film is interposed between an anode and a cathode. Holes are injected via the anode, and electrons are injected via the cathode, and then the electrons and the holes combine in the organic light emission layer so that excitons are formed therein and emit light while recombining with each other.
In order to realize a full-color organic light emitting display apparatus, an independent light emission method, a color filter method, a color conversion method, or the like may be used. The independent light emission method involves thermally depositing each red (R), green (G), and blue (B) light emitting material by using a metal shadow mask having an elaborate pattern so as to realize R, G, and B colors. The color filter method involves forming a white light emission layer and then patterning R, G, and B color filters so as to realize R, G, and B colors. The color conversion method involves forming a blue light-emission layer and then using a color conversion layer for converting a blue color into green and red colors so as to realize R, G, and B colors.
In an organic light emitting display apparatus using the color filter method, an efficiency of an emitted white light decreases while passing through a color filter, and thus a highly efficient white light emitting material is required, and an overall efficiency is low, compared to a fine patterning method using the metal shadow mask.
With regard to the independent light emission method that involves depositing and patterning the R, G, and B light emitting materials by using a fine metal shadow mask, when the size and resolution of a display are increased, it is difficult to enlarge an organic light emission panel due to difficulties in manufacturing the fine metal shadow mask. Also, in order to deposit an auxiliary layer and the R, G, and B light emitting materials, an elaborate alignment equipment is used. In this regard, when a pixel of a thin-film transistor (TFT) substrate and the fine metal shadow mask are aligned, a defective pixel may be formed due to damaged organic materials that were previously deposited. Also, a large fine metal shadow mask is difficult to manufacture and is very expensive.